/*
 * This file is part of the KubeVirt project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Copyright 2018 Red Hat, Inc.
 *
 */

package main

import (
	"bufio"
	"encoding/base64"
	"flag"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"
	"text/template"
	"time"

	"github.com/spf13/pflag"

	v1 "k8s.io/api/core/v1"

	"kubevirt.io/kubevirt/pkg/virt-operator/resource/generate/components"
	"kubevirt.io/kubevirt/pkg/virt-operator/resource/generate/rbac"
	"kubevirt.io/kubevirt/tools/util"
)

const (
	customImageExample   = "Examples: some.registry.com@sha256:abcdefghijklmnop, other.registry.com:tag1"
	shaEnvDeprecationMsg = "This argument is deprecated. Please use virt-*-image instead"
)

type templateData struct {
	Namespace                          string
	CDINamespace                       string
	CSVNamespace                       string
	DockerTag                          string
	DockerPrefix                       string
	ImagePrefix                        string
	ImagePullPolicy                    string
	Verbosity                          string
	CsvVersion                         string
	QuayRepository                     string
	ReplacesCsvVersion                 string
	OperatorDeploymentSpec             string
	OperatorCsv                        string
	OperatorRules                      string
	KubeVirtLogo                       string
	PackageName                        string
	CreatedAt                          string
	RunbookURLTemplate                 string
	PriorityClassSpec                  string
	FeatureGates                       []string
	InfraReplicas                      uint8
	TestImageReplicas                  string
	GeneratedManifests                 map[string]string
	VirtOperatorImage                  string
	VirtApiImage                       string
	VirtControllerImage                string
	VirtHandlerImage                   string
	VirtLauncherImage                  string
	VirtExportProxyImage               string
	VirtExportServerImage              string
	VirtSynchronizationControllerImage string
	GsImage                            string
	PrHelperImage                      string
	SidecarShimImage                   string
}

func main() {
	namespace := flag.String("namespace", "", "")
	csvNamespace := flag.String("csv-namespace", "placeholder", "")
	cdiNamespace := flag.String("cdi-namespace", "", "")
	dockerPrefix := flag.String("container-prefix", "", "")
	imagePrefix := flag.String("image-prefix", "", "")
	dockerTag := flag.String("container-tag", "", "")
	csvVersion := flag.String("csv-version", "", "")
	imagePullPolicy := flag.String("image-pull-policy", "IfNotPresent", "")
	verbosity := flag.String("verbosity", "2", "")
	genDir := flag.String("generated-manifests-dir", "", "")
	inputFile := flag.String("input-file", "", "")
	processFiles := flag.Bool("process-files", false, "")
	processVars := flag.Bool("process-vars", false, "")
	kubeVirtLogoPath := flag.String("kubevirt-logo-path", "", "")
	packageName := flag.String("package-name", "", "")
	quayRepository := flag.String("quay-repository", "", "")
	runbookURLTemplate := flag.String("runbook-url-template", "", "")
	featureGates := flag.String("feature-gates", "", "")
	infraReplicas := flag.Uint("infra-replicas", 0, "")
	testImageReplicas := flag.String("test-image-replicas", "0", "")
	virtOperatorImage := flag.String("virt-operator-image", "", "custom image for virt-operator")
	virtApiImage := flag.String("virt-api-image", "", "custom image for virt-api. "+customImageExample)
	virtControllerImage := flag.String("virt-controller-image", "", "custom image for virt-controller. "+customImageExample)
	virtHandlerImage := flag.String("virt-handler-image", "", "custom image for virt-handler. "+customImageExample)
	virtLauncherImage := flag.String("virt-launcher-image", "", "custom image for virt-launcher. "+customImageExample)
	virtExportProxyImage := flag.String("virt-export-proxy-image", "", "custom image for virt-export-proxy. "+customImageExample)
	virtExportServerImage := flag.String("virt-export-server-image", "", "custom image for virt-export-server. "+customImageExample)
	virtSynchronizationControllerImage := flag.String("virt-synchronization-controller-image", "", "custom image for virt-synchronization-controller. "+customImageExample)
	gsImage := flag.String("gs-image", "", "custom image for gs. "+customImageExample)
	prHelperImage := flag.String("pr-helper-image", "", "custom image for pr-helper. "+customImageExample)
	sidecarShimImage := flag.String("sidecar-shim-image", "", "custom image for sidecar-shim. "+customImageExample)

	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
	pflag.CommandLine.ParseErrorsWhitelist.UnknownFlags = true
	pflag.Parse()

	if path := os.Getenv("BUILD_WORKSPACE_DIRECTORY"); path != "" {
		if err := os.Chdir(path); err != nil {
			panic(err)
		}
	}

	if !(*processFiles || *processVars) {
		panic("at least one of process-files or process-vars must be true")
	}

	data := templateData{
		GeneratedManifests: make(map[string]string),
	}

	if *processVars {
		data.Namespace = *namespace
		data.CSVNamespace = *csvNamespace
		data.CDINamespace = *cdiNamespace
		data.DockerTag = *dockerTag
		data.DockerPrefix = *dockerPrefix
		data.ImagePrefix = *imagePrefix
		data.ImagePullPolicy = *imagePullPolicy
		data.Verbosity = fmt.Sprintf("\"%s\"", *verbosity)
		data.TestImageReplicas = fmt.Sprintf("\"%s\"", *testImageReplicas)
		data.CsvVersion = *csvVersion
		data.QuayRepository = *quayRepository
		data.RunbookURLTemplate = *runbookURLTemplate
		data.OperatorRules = getOperatorRules()
		data.KubeVirtLogo = getKubeVirtLogo(*kubeVirtLogoPath)
		data.PackageName = *packageName
		data.CreatedAt = getTimestamp()
		data.ReplacesCsvVersion = ""
		data.OperatorDeploymentSpec = getOperatorDeploymentSpec(data, 2)
		data.PriorityClassSpec = getPriorityClassSpec(2)
		data.VirtOperatorImage = *virtOperatorImage
		data.VirtApiImage = *virtApiImage
		data.VirtControllerImage = *virtControllerImage
		data.VirtHandlerImage = *virtHandlerImage
		data.VirtLauncherImage = *virtLauncherImage
		data.VirtExportProxyImage = *virtExportProxyImage
		data.VirtExportServerImage = *virtExportServerImage
		data.VirtSynchronizationControllerImage = *virtSynchronizationControllerImage
		data.GsImage = *gsImage
		data.PrHelperImage = *prHelperImage
		data.SidecarShimImage = *sidecarShimImage
		if *featureGates != "" {
			data.FeatureGates = strings.Split(*featureGates, ",")
		}
		if *infraReplicas != 0 {
			data.InfraReplicas = uint8(*infraReplicas)
		}

	} else {
		// keep templates
		data.Namespace = "{{.Namespace}}"
		data.CDINamespace = "{{.CDINamespace}}"
		data.DockerTag = "{{.DockerTag}}"
		data.DockerPrefix = "{{.DockerPrefix}}"
		data.ImagePrefix = "{{.ImagePrefix}}"
		data.ImagePullPolicy = "{{.ImagePullPolicy}}"
		data.Verbosity = "{{.Verbosity}}"
		data.TestImageReplicas = "{{.TestImageReplicas}}"
		data.CsvVersion = "{{.CsvVersion}}"
		data.QuayRepository = "{{.QuayRepository}}"
		data.ReplacesCsvVersion = "{{.ReplacesCsvVersion}}"
		data.OperatorDeploymentSpec = "{{.OperatorDeploymentSpec}}"
		data.OperatorCsv = "{{.OperatorCsv}}"
		data.OperatorRules = "{{.OperatorRules}}"
		data.KubeVirtLogo = "{{.KubeVirtLogo}}"
		data.PackageName = "{{.PackageName}}"
		data.CreatedAt = "{{.CreatedAt}}"
		data.VirtApiImage = "{{.VirtApiImage}}"
		data.VirtControllerImage = "{{.VirtControllerImage}}"
		data.VirtHandlerImage = "{{.VirtHandlerImage}}"
		data.VirtLauncherImage = "{{.VirtLauncherImage}}"
		data.VirtExportProxyImage = "{{.VirtExportProxyImage}}"
		data.VirtExportServerImage = "{{.VirtExportServerImage}}"
		data.VirtSynchronizationControllerImage = "{{.VirtSynchronizationControllerImage}}"
		data.GsImage = "{{.GsImage}}"
		data.PrHelperImage = "{{.PrHelperImage}}"
		data.SidecarShimImage = "{{.SidecarShimImage}}"
	}

	if *processFiles {
		manifests, err := os.ReadDir(*genDir)
		if err != nil {
			panic(err)
		}

		for _, manifest := range manifests {
			if manifest.IsDir() {
				continue
			}
			b, err := os.ReadFile(filepath.Join(*genDir, manifest.Name()))
			if err != nil {
				panic(err)
			}
			data.GeneratedManifests[manifest.Name()] = string(b)
		}
	}

	tmpl := template.Must(template.ParseFiles(*inputFile))
	err := tmpl.Execute(os.Stdout, data)
	if err != nil {
		panic(err)
	}
}

func getOperatorRules() string {
	rules := rbac.NewOperatorClusterRole().Rules
	writer := strings.Builder{}
	for _, rule := range rules {
		err := util.MarshallObject(rule, &writer)
		if err != nil {
			panic(err)
		}
	}
	return fixResourceString(writer.String(), 14)
}

func getPriorityClassSpec(indentation int) string {
	priorityClassSpec := components.NewKubeVirtPriorityClassCR()
	writer := strings.Builder{}
	err := util.MarshallObject(priorityClassSpec, &writer)
	if err != nil {
		panic(err)
	}
	return fixResourceString(writer.String(), indentation)
}

func getOperatorDeploymentSpec(data templateData, indentation int) string {
	version := data.DockerTag
	deployment := components.NewOperatorDeployment(
		data.Namespace,
		data.DockerPrefix,
		data.ImagePrefix,
		version,
		data.Verbosity,
		data.DockerTag,
		data.RunbookURLTemplate,
		data.VirtApiImage,
		data.VirtControllerImage,
		data.VirtHandlerImage,
		data.VirtLauncherImage,
		data.VirtExportProxyImage,
		data.VirtExportServerImage,
		data.VirtSynchronizationControllerImage,
		data.GsImage,
		data.PrHelperImage,
		data.SidecarShimImage,
		data.VirtOperatorImage,
		v1.PullPolicy(data.ImagePullPolicy))

	writer := strings.Builder{}
	err := util.MarshallObject(deployment.Spec, &writer)
	if err != nil {
		panic(err)
	}
	spec := writer.String()

	return fixResourceString(spec, indentation)
}

func fixResourceString(in string, indention int) string {
	out := strings.Builder{}
	scanner := bufio.NewScanner(strings.NewReader(in))
	for scanner.Scan() {
		line := scanner.Text()
		// remove separator lines
		if !strings.HasPrefix(line, "---") {
			// indent so that it fits into the manifest
			// spaces is is indention - 2, because we want to have 2 spaces less for being able to start an array
			spaces := strings.Repeat(" ", indention-2)
			if strings.HasPrefix(line, "apiGroups") {
				// spaces + array start
				out.WriteString(spaces + "- " + line + "\n")
			} else {
				// 2 more spaces
				out.WriteString(spaces + "  " + line + "\n")
			}
		}
	}
	return out.String()
}

func getKubeVirtLogo(path string) string {
	file, err := os.Open(path)
	if err != nil {
		panic(err)
	}

	// Read entire file into byte slice.
	reader := bufio.NewReader(file)
	content, err := io.ReadAll(reader)
	if err != nil {
		panic(err)
	}

	// Encode as base64.
	encoded := base64.StdEncoding.EncodeToString(content)
	return encoded
}

func getTimestamp() string {
	return time.Now().UTC().Format("2006-01-02T15:04:05Z")
}
